Honestly I don't know how she won MVP. If there was anything memorable about her performance it was that her dress made her look like she was singing for two.
For me I'd say the top performance was by Miyo -- she was amazing.
Masaki was great as well. Her energy reminds me a little bit of Miley Cyrus's somehow, the way she takes over the stage with that blinding smile and just does whatever, like she knows she's a star whether or not you acknowledge it.
Kiki oddly impressed me too -- there wasn't anything spectacular, she just did everything right, looked gorgeous, sang well, had a cute prop, it was professional-level entertainment.
Just missing the top tier, I'd put Layla slaying Mugen Climax. She's never going to be a front girl but damned if she isn't going to try her best.
Below that, when it comes to cuteness, I could watch Reina

and Utano's

sets countless times.
Haga's another one who has been bringing it after a long spell of just kind of lurking in the sidelines. I think I remember one time Moh saying Sakura had the most extreme glow-up in H!P. Haga might be trying to challenge that.
I appreciated Shion's and Erina's little creative touches to make their turns memorable. Erina doesn't quite manage to look like she's enjoying herself, but if nothing else, the girl can eat a big bowel of ramen and still flex a six-pack as tight as a drum.
Sakura and Ruru, who I'd expect to dominate in solo performances, were both sadly underwhelming.
Kanatomo can effortlessly outclass mere mortal humans in terms of beauty, but as a singer....sigh. There was an artist from the 1980's called Teena Marie who was part of the Rick James funk scene, extremely well-regarded back in her day but when I hear her music now with her high pitched warble, I don't get it. That's who Tomoko's voice reminds me of.